The Guardian asked a range of commentators the following questions about a green investment bank, an ideal widely talked about for the UK. 1. How should it most effectively be set up?

2. What should it use its financial resources to support?

My response was

1, The German state investment bank KfW is an attractive model. This entity lent €60bn last year, almost half of which went to companies involved in environmental protection of one form or another. It raises money on the international capital markets but its conservative policies and long-term perspective have meant it has been able to continue supporting smaller companies and environmental projects throughout the last two difficult years. If implemented here, our equivalent should be located outside London, have lending offices spread across the UK and offer private individuals a chance to invest in its activities.

2. In 2009 KfW put about €9bn into building refurbishment. Its activities have been geared towards helping property companies and social landlords improve the poor insulation standards of post-war German housing and commercial property. It has helped improve many hundreds of thousands of homes, providing more comfortable accommodation that it is much cheaper to run. KfW's lending has also created an effective and flexible eco-refurbishment industry. This has improved employment and skills, particularly in the less prosperous eastern parts of the country. We should copy the German emphasis on housing renovation as a primary activity of the bank, rather than let the UK entity focus on risky venture capital investments